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Re: gomp slowness
On Fri, 2007-11-02 at 07:39 -0700, Ian Lance Taylor wrote:
> skaller <skaller@users.sourceforge.net> writes:
> In a C executable, TLS requires one extra machine register.
You mean gcc?
> TLS
> variables are accessed via offsets from that register. So what's the
> significant difference between that and your proposal?
I wasn't making a proposal.
> The only way I can interpret your comments is that you are assuming
> that all TLS is Global Dynamic (e.g., accessed from a dlopen'ed shared
> library). But stack based thread local storage won't work for
> dlopen'ed shared libraries at all.
No, I was assuming implementation of a call like:
void *pthread_getspecific(pthread_key_t key);
> I think you need to look at the TLS access code before deciding that
> it has bad performance.
You already said it costs a register? That's a REALLY high cost
to pay to support badly designed software.
--
John Skaller <skaller at users dot sf dot net>
Felix, successor to C++: http://felix.sf.net